The main shaft of a transmission usually comprises a bore formed along its center axis via which from a differential gear lubricating oil can be introduced into needle bearings of the drive organs and the synchronizers arranged on the main shaft. The needle bearings exclusively serve to absorb radial forces. In addition to the needle bearings for the drive organs and the synchronizers at least one roller bearing is arranged on the main shaft which cannot only absorb radial forces but also axial forces and thus can also make available a mounting of the main shaft on the housing surrounding the main shaft. The roller bearing is usually supplied with oil via an oil channel in that lubricating oil in form of oil splashes is transported on to the roller bearing for lubricating the roller bearing. The quantity of the lubricating oil transported on to the roller bearing cannot be accurately set so that it can happen that the roller bearings are not adequately supplied with lubricating oil, which can result in increased wear of the roller bearings.
At least one object therefore is to make available a drive unit of a transmission wherein a reduction of the wear of a roller bearing can be achieved. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.